Exam N10-008 topic 1 question 417 discussion

802.11n is one of two of the WiFi standards that can operate on 2.4 AND 5 GHz but it's the only one that is listed and so therefore, it's D since they wanted to have "a wide range of devices."

Cisco Web What are advantages of 802.11ac over 802.11n? With its new 5-GHz spectrum, 802.11ac achieves faster speeds for data throughput and provides more bandwidth for additional computers, wireless devices, and Internet of Things (IoT) devices to come online. Is 802.11ac backward- and forward-compatible? Each new Wi-Fi standard effectively absorbs previous versions. Depending on client hardware or network conditions, 802.11ac operates with 802.11n and any other previous 802 standard when necessary. Is 802.11ac backward- and forward-compatible? This compatibility will extend forward as well: Wi-Fi 6 will be backward-compatible with 802.11ac, with performance conforming to the older standard. By switching between 2.4-GHz and 5-GHz bands, 802.11ac can dynamically optimize network performance based on network usage. And by using beamforming, 802.11ac results in less interference for transmissions and lower power demands from routers.

I know that CompTIA wants me to answer D, but everyone should know that modern routers that are labeled as 802.11ac can operate on both 2.4 and 5 GHz ranges, where on the 2.4 GHz range the router reverts back to the 802.11n standard. Remember CompTIA hates you and wants you to fail.

ac is the fastest and most compatible. It will have n included with the router options. AC is backwards compatible